This invention relates to an improved wire connecting system, more precisely a wire connecting block, where a known commercial system is available and is sometimes identified as the 110 connector system. The present invention offers superior wire retention capabilities to those available in the market.
Such a wire connecting block is used in the telephone industry to electrically interconnect a set of first conductors to an associated set of second conductors. An early example of a wire connecting block is taught in U.S. Pat. No. 3,611,264. The connector thereof includes an indexing strip and a connecting block, the latter of which carries a plurality of slotted beam contacts. The indexing strip has a plurality of uniform height, spaced-apart teeth along its length. These teeth aid in indexing a first set of conductors. A corresponding plurality of uniform height, spaced-apart teeth carried by the connecting block serve to index a second set of conductors to be cross-connected through the slotted beam contacts to the first set of conductors.
The general design and operation of a 110 connector system have remained unchanged over the years to ensure compatibility with a commercially available, manual, wire termination tool, and existing telephone equipment. Two generally accepted tools to accomplish the termination process are the hand tools available through AT&T, Model No. Harris-Dracon D-814, and KRONE, Model No. LSA-PLUS No. 6417 2 055-01. Briefly, each such tool is designed to provide throughout essentially the width of the connector housing, a normal force to a strategically placed insulated wire, relative to the slotted beam contact, to insert same into the contact situated within the housing. It will be appreciated that a considerable normal force must be applied to the contact to effect termination thereto by the displacing of the conductor insulation, typically polyethylene and the like, and pushing such conductor into the slot between the contact arms. In the wire connecting blocks sold commercially, most experience considerable "play" in the seated contacts.
In a recently issued patent, U.S. Pat. No. 5,409,404, assigned to the assignee hereof, and which contents are incorporated herein by reference, there is described a system for eliminating contact play in the housing. Briefly, the connector housing is defined by a pair of side walls, having a plurality of through cavities, where the length of the cavities are characterized by a first uniform width over a portion of its length, a second portion having a uniform width greater than the first uniform width, and an angled wall transition portion between the uniform portions. The housing also includes a like plurality of thin walled sections along one of the side walls, where each of the thin walled sections is aligned with a corresponding angled wall transition portion within a given cavity. The slotted beam planar contact to be received therein comprises a mid body portion and a pair of opposing end portions each containing an insulation displacing slot for receiving a conductor. The mid body portion is provided with a lance struck therefrom and angled to abut the angled wall transition portion. By this arrangement the contact is secured against movement in a first direction as pressure is applied thereto during conductor termination. Further, the thin walled sections are partially severed from the respective side wall by a hand tool to allow hinging movement thereof into the respective cavities adjacent the lances. This action secures the contact against movement in a second direction, i.e. in the opposite direction during termination of the other set of conductors.
U.S. Pat. No. 4,964,812 is also directed to a system, though more complex and labor intense, for improving the retention of the contact within the housing body. The housing body is provided with retention means for positioning and retaining the slotted beam contacts. These retention means comprise retention posts which are flash molded onto the side of the housing body during the molding operation. Upon insertion and positioning of a plurality of beam contacts within the connecting block housing, pressure is exerted against the retention posts thereby breaking the flash molding and forcing the posts through positioning holes in the contacts. Thereafter, the post tips are peened in place providing permenent but free floating connection between the contacts and the connecting block housing.
While the foregoing represent needed improvements to the conventional wiring blocks, neither is concerned with improving the wire retention capabilities of a wiring block that remains compatible with existing termination tools. Such improved capabilities of this invention will become apparent to those skilled in the art from the following specification, particularly when read in conjunction with the accompanying drawings.